Abstract
In-situ transmission electron microscopy of domain motion in thinned BaTiO3 and KNbO3 shows that curved ferroelectric domains move more: readily under low electric fields than do straight domain walls. We show that this relative motility arises because curved domain walls support a Maxwellian displacement charge and therefore experience a direct pressure that is proportional to the electric field E. Conversely, untilted charge-neutral domain walls experience a pressure proportional to E-3 due to induced displacement charge. and therefore tend to resist motion at low fields.
Any physical process that lends to an increase in density of the immobile charge-free domain wails, relative to the more mobile curved domain walls, could lead to an increase in overall resistance to domain switching, providing an intrinsic contribution to ferroelectric fatigue.